Researchers have found a new class of drugs can improve the ability of particles in the blood which can increase so-called ‘good’ cholesterol’s ability to clear away fat from blood vessel walls.

The reduction of furring up of blood vessels – called atherosclerosis by medical experts - relies on reducing the amount of fat laid down in the vessel wall for example by taking statins or by improving the efficacy of good cholesterol which carries fat deposits away from the blood vessel lining.

Patients with higher levels of good cholesterol have a lower risk of heart attacks.

In this new study, published in the European Heart Journal and the largest one carried out so far to look at function, experts examined the effects of these drugs - called CETP inhibitors - on the special particles and the overall good cholesterol levels.

Professor Kausik Ray, of St George's, University of London, said: “Generally, medical experts have attempted to develop drugs that raise good cholesterol levels believing that raising good cholesterol would prevent heart attacks. Some of these drugs turned out to be harmful whereas others showed no benefit but also no harm despite raising good cholesterol by 30%.

The question remains therefore is this viable method for reducing heart attacks and strokes.

Our study looked at what the so called good cholesterol particles did and whether the drug improved the function or efficiency of these particles.

“We found that the good cholesterol particles did increase in number and function but by a modest 10% despite raising good cholesterol overall by 30%.

“So there is a discrepancy between cholesterol levels in good particles and how they are working and simply raising good cholesterol with having significant effect on function may not be enough.

“It is possible that the way that these particles work is more important than the overall levels of cholesterols they carry and only by increasing function much more are these types of drugs likely to be effective.

“Importantly this also suggests that more work needs to be done to see how function is related to heart attacks.”